At the Terra Foundation website (remember the Horturba table?) we found two interesting alternatives to take advantage of the solar heat to cook outdoors without electricity or gas expenses, and reducing smoke emissions.
First, the parabolic solar kitchen KSol is a panel similar to a television antenna that concentrates solar light in the center of it (see sample in the extended). It comes in two models which have a diameter of 1 and 1,4m respectively, are equivalent to a 600 and 300 W power, and can reach a maximum temperature of 200 degrees Celsius... It looks a bit uncomfortable, but it can be worth giving it a chance. With the smallest model, you can obtain enough heat to prepare coffee for 6 people in 10 minutes. Their prices are 98 and 153 euros, without including shipping.
On the other hand, Sun Cook is a device close to a grill that redirects solar rays towards the center by a series of aluminum mirrors. We have to say it could be made in a more eco material, since some of its parts are plastic, but it looks like a greener alternative to making lots of smoke. The oven is 59 cm deep, 57 cm long and 28 cm high when closed. It can reach temperatures of up to 150 degrees Celsius, which would allow you to cook for up to 6 people. Plus, it's possible to bake without the need to be present controlling it. Its price, without shipping, is 210 euros. ::Terra Foundation